Follicle-stimulating hormone (FSH) luteinising hormone (LH) and chorionic gonadotrophin (CG) are injectable proteins falling into the class of gonadotrophins. FSH, LH and hCG are used alone and in combination in the treatment of infertility and reproductive disorders in both female and male patients.
In nature, FSH and LH are produced by the pituitary gland. For pharmaceutical use, FSH and LH and their variants may be produced recombinantly (rFSH and rLH), or they may be produced from the urine of postmenopausal women (uFSH and uLH).
FSH is used in female patients in ovulation induction (OI) and in controlled ovarian hyperstimulation (COH) for assisted reproductive technologies (ART). In a typical treatment regimen for ovulation induction, a patient is administered daily injections of FSH or a variant (about 75 to 300 IU FSH/day) for a period of from about 6 to about 12 days. In a typical treatment regimen for controlled ovarian hyperstimulation, a patient is administered daily injections of FSH or a variant (about 150-600 IU FSH/day) for a period of from about 6 to about 12 days.
FSH is also used to induce spermatogenesis in men suffering from oligospermia. A regimen using 150 IU FSH 3 times weekly in combination with 2,500 IU hCG twice weekly has been successful in achieving an improvement in sperm count in men suffering from hypogonadotrophic hypogonadism1.
LH is used in female patients in combination with FSH in OI and in COH, particularly in those patients having very low endogenous LH levels or resistance to LH, such as women suffering from hypogonadotrophic hypogonadism (HH, WHO group I) or older patients (i.e. 35 years or older), and patients in which embryo implantation or early miscarriage is a problem. LH in combination with FSH has traditionally been available in a preparation called human menopausal gonadotrophins (hMG) extracted from the urine of postmenopausal women. hMG has a 1:1 ratio of FSH:LH activity.
CG acts at the same receptor as LH and elicits the same responses. CG has a longer circulation half-life than LH and is therefore commonly used as a long-acting source of LH-activity. CG is used in OI and COH regimens to mimic the natural LH peak and trigger ovulation. An injection of human chorionic gonadotrophin (hCG) is used to trigger ovulation at the end of stimulation with FSH or a mixture of FSH and LH. CG may also be used together with FSH during stimulation for OI and COH, in order to provide LH-activity during stimulation in patients in which LH-activity is desirable, such as those mentioned above.
FSH, LH and CG are members of the heterodimer, glycoprotein hormone family that also includes thyroid stimulating hormone (TSH). The members of this family are heterodimers, comprising an α- and a β-subunit. The subunits are held together by noncovalent interactions. The human FSH (hFSH) heterodimer consists of (I) a mature 92 amino acid glycoprotein alpha subunit, which also is common to the other human family members (i.e., chorionic gonadotrophin (“CG”), luteinising hormone (“LH”) and thyroid stimulating hormone (“TSH”); and (ii) a mature 111 amino add beta subunit that is unique to FSH2. The human LH heterodimer consists of (i) the mature 92 amino acid glycoprotein alpha subunit; and (ii) a mature 112 beta subunit that is unique to LH3. The alpha and beta subunits of the glycoproteins may be prone to dissociate in formulations, due to interaction with a preservative, surfactant and other excipients. Dissociation of the subunits leads to loss of biological potency4.
FSH is formulated for intramuscular (IM) or subcutaneous (SC) injection. FSH is supplied in lyophilised (solid) form in vials or ampoules of 75 IU/vial and 150 IU/vial with a shelf life of one and a halt to two years when stored at 2-25° C. A solution for injection is formed by reconstituting the lyophilised product with water for injection (WFI). For ovulation induction or controlled ovarian hyperstimulation, daily injections with starting doses of 75 IU to 600 IU are recommended for up to about ten days. Depending on the patients response, up to three cycles of treatment with increasing doses of FSH can be used. With lyophilised formulations, the patient is required to reconstitute a new vial of lyophilised material with diluent and administer it immediately after reconstitution on a daily basis [Package insert N1700101A, published in February 1996, for Fertinex™ (urofollitropin for injection, purified) for subcutaneous injection, by Serono Laboratories, Inc., Randolph, Mass.].
FSH has also been formulated in both single-dose and multi-dose liquid formats, in vials, or ampoules. Single dose formats must remain stable and potent in storage prior to use. Multi-dose formats must not only remain stable and potent in storage prior to use, but must also remain stable, potent and relatively free of bacteria over the multiple-dose use regimen administration period, after the seal of the ampoule has been compromised. For this reason, multi-dose formats often contain a bacteriostatic agent.
LH is formulated for intramuscular (IM) or subcutaneous (SC) injection. LH is supplied in lyophilised (solid) form in vials or ampoules of 75 IU/vial with a shelf life of one and a half to two years when stored at 2-25° C. A solution for injection is formed by reconstituting the lyophilised product with water for injection (WFI). For ovulation induction or controlled ovarian hyperstimulation, in conjunction with FSH, daily injections with starting doses of 75 IU to 600 IU LH are recommended for up to about ten days.
EP 0 618 808 (Applied Research Systems ARS Holding N.V.) discloses a pharmaceutical composition comprising a solid intimate mixture of gonadotrophin and a stabilising amount of sucrose alone or in combination with glycine.
EP 0 814 841 (Applied Research Systems ARS Holding N.V.) discloses a stable, liquid pharmaceutical composition comprising recombinant human chorionic gonadotrophin (hCG) and a stabilizing amount of mannitol.
EP 0 448 146 (AKZO N.V.) discloses a stabilized gonadotrophin containing lyophilisate comprising one part by weight of a gonadotrophin; and 200 to 10,000 parts by weight of a dicarboxylic acid salt stabilizer associated with the gonadotrophin.
EP 0 853 945 (Akzo Nobel N. V.) discloses a liquid gonadotrophin-containing formulation characterised in that the formulation comprises a gonadotrophin and stabilising amounts of a polycarboxylic acid or a salt thereof and of a thioether compound.
WO 00/04913 (Eli Lilly and Co.) discloses a formulation comprising FSH or an FSH variant, containing an alpha and beta subunit and a preservative selected from the group consisting of phenol, m-cresol, p-cresol, o-cresol, chlorocresol, benzyl alcohol, alkylparaben (methyl, ethyl, propyl, butyl and the like), benzalkonium chloride, benzethonium chloride, sodium dehydroacetate and thimerosal, or mixtures thereof in an aqueous diluent.
There remains a need for stable liquid formulations of FSH or FSH variants, and mixtures of FSH and LH, either for single dose or multiple dose administration.